Your diesel car could become non-compliant even before 10 year scrapping age, here’s how! – Times of India

A recent study led by Rajeev Kumar Mishra, assistant professor for the Environmental Engineering Department at the Delhi Technological University suggests that diesel cars start emitting dangerous pollutants much earlier than the currently set 10 year scrapping age in the capital city. While age is a factor, the mileage of a diesel vehicle also matters and can render a vehicle unfit even before the completion of its scrapping age. The study was published in Springer’s Environmental Science and Pollution Research journal.

The research study was conducted across 460 diesel cars, registered in various RTOs in the capital city. It was found that, after 7.5 years of age or running 95,000 km, the cars became non-compliant with BS-IV emission norms. The same cars after 9 years of age or running over 1,25,000 km would become BS-III non-compliant. Non-compliance of BS-III norms would also disallow owners to get pollution certification for their vehicles earlier than the prescribed 10 year scrapping age. While the predictive age for BS-III violation is close to the 10 year benchmark, the possibility of BS-IV violation at just 7.5 years could be a point of concern.

The research also found that periodical maintenance plays a major role in how early a diesel vehicle becomes non-compliant with BS-IV emission norms. Delhi currently has 9 lakh diesel cars plying on its roads and the BS-IV cutoff is strict, allowing only 50 HSU (Hartridge Smoke Units) to be emitted per vehicle. Under the BS-III norms, this used to be 65 HSU units. While BS-III type engine car fleet comprises only 5 to 8 percent of the Total diesel car population in Delhi, the results still make a strong case for the scrapping policy to be revised based on mileage of a car.

But what about private cars that are well maintained? According to co-researcher Abhinav Pandey, such diesel cars that were older and had clocked more mileage, were found to be compliant with both BS-IV and BS-III norms. Maintenance factors include a vehicle’s engine tuning, regular servicing, proper upkeep of emission control systems such as catalytic converters and diesel particulate filters that trap gaseous pollutants and PM 2.5 and PM10 particulates emitted from diesel engines.